Javascript question

How do you add some content in a specific place in Javascript at the user's bequest? I'm writing a sort of CSS designer with the idea that it shows the user what the style looks like by writing it to a file and then loading it (using PHP). The thing is I want it to actually be useful, so it needs to be able to have as many elements and properties as the user wants. I know that trick where you have an empty <div> and set its innerHTML member but that will leave me a set number, and I don't want to just stick billions and billions of <div> tags inside my code (its already messy enough).

tl; dr how do I dynamically instert code into a webpage at a set position but allowing an arbitrary number of insertions?

>>15
jquery
custom templating function with tiny html templates stored in <script type="text/template"> tags for more involved dynamic stuff
Why the fuck do people love overcomplicating things?

Get the Node of the element you want to add into with getElementById or whatever suitable. appendChild() your new element.

Simple as that.

Firefox has a DOM Inspector you can use to see what it's doing.